This invention relates to row crop processing implements and to apparatus for guiding them to pass down the field in precise parallel relationship with respect to the plant rows which are being processed. The apparatus involves means for establishing guide paths in the earth at the time the position and direction of the crop rows is being established; and means for subsequently guiding the processing implements along the rows, utilizing the guide paths previously formed.
This broad general idea is old. See U.S. Pat. No. 3,840,076, granted in October of 1974 to Capehart. In that patent, a forwardly hooked shaped cutter blade 20 is pulled through the earth on a seed planter to establish a guide path or slit while the planter is establishing the positioning of the rows. A lecticular disc 28, mounted on a subsequently used processing implement is employed to try to follow the guide path or slit 26. The disc rotates on a horizontal axis perpendicular to the direction of travel of the implement, and the lenticular disc and the row crop processing implement are so related that the disc supports a substantial portion of the weight of the implement "to thereby bodily and directly move" the "implement laterally in response to changes in direction of" the "slit." The structure of the Capehart patent is, however, subject to substantial operating difficulties.
First, the forwardly hooking cutter blade 20 has to extend "downwardly a very substantial distance into soil 24, preferably to a depth of the order of 8 to 10 inches . . . " In conditions where the moisture in the soil and near the surface of the soil is critical, as it always is in the planting and growing of crops, a slit of this depth will allow substantial quantities of rain and/or irrigation moisture to rapidly drain below the area where it will be of maximum help to establish and support the growth of the row crops in question.
Furthermore, the establishment of a guide path or slit 26 as shown in Capehart simply by pulling a blade 20 through the soil, even where that path is supposedly reinforced and compacted by a further lenticular disc 28 proceeding directly in its wake, does not produce the kind of shallow straight-sided trench which has been found useful and necessary in the subsquent guiding of row processing implements along row crops. Any trash or roots or other obstructions encountered by such a cutter blade will tend to pivot right around the blade and come to rest just behind it. This is similar to the action obtained by pulling one's vertically held finger through soft sand on a beach, for example. The subsequent action of the closely following lenticular disc is simply to attempt to compact a V-shape guide path or "slit" behind where the cutter blade 20 has disturbed the soil.
In contrast, the apparatus of the present invention presents a guide plate or block having a wedge-shaped leading edge and a flat plate-like trailing portion of some substantial length behind the wedge. Upon drawing such an implement or guide making block through the soil, any trash or debris or any roots or rocks will tend to be pushed to the side by the wedge and will tend to move around behind the wedge. However, this they cannot do since they immediately encounter the flat plate-like trailing portion of the guide block which slides past them and the surrounding earth, tightly packing vertical side walls of a guide path or trench to bind those obstructions together with the earth in the trench side walls. By the time the guide block has past, then, substantial vertical trench side walls are justified and established.
Subsequent wheels or rollers acting along the top of the trench established by the apparatus of the present invention do no more than firm up or compact the top edges of the vertical side walls of the trench; and trench cleaning spikes or teeth trailed down the guide paths or trenches subsequently do no more than dislodge any debris which has fallen into the trench to force it to one side or the other of that guide path.
In attempting to follow the guide path or slit 26 with a lenticular disc 28 as demonstrated in the Capehart patent, severe difficulties are encountered. In wet or damp soil conditions, the rolling lenticular disc necessarily picks up great quantities of mud, and carries that mud around to the point where the disc tends to be lifted out of the guide path and to lose its direction relative to that path or slit. Because the lenticular disc is a sharpened disc, as soon as it begins to lose direction with respect to the guide path or slit, whether it is carrying mud in wet conditions or not, it will grab or cut into the solid earth and will cause a severe drag in the direction in which it has deviated from the guide path, thus wrenching the vehicle out of its proper track, thus acting to destroy the row crops as the implement blades are carried into the rows.
This is exactly and precisely opposite to the action of a flat, substantially elongated guide plate being drawn through a previously established guide path such as a trench with vertical side walls. Using such a guide block, the continuous sliding action of that block as it is pulled through wet or damp soil, for example, causes the block to be continuously wiped clean and and causes no tendency to build up which will interfere with the action of the guide block in guiding the row processing implement.
Furthermore, should the guide block for any reason start to move out of its trench, or should the guide block be started down the row before it is actually aligned with the trench, the lack of lateral support of the earth on the side of the guide block toward the trench, as this earth is forced into the trench, for example, and the firm support of the earth on the side of the guide block away from the trench immediately causes the guide block to move toward the trench thus centering the implement precisely with respect to the crop rows.
The tendency of structures such as disclosed in the Capehart patent to cut into the side of the guide path and to climb out of the path is particularly pronounced when such structure is attempted to be used to cultivate row crops which lie on a field or hillside in which the tractor and cultivating implement are tilted in direction transverse to the direction of the rows. In this situation it is necessary to steer the towing tractor up just as close as possible to the uphill side of the rows in an effort, often a vain effort, to prevent the processing implement from damaging the downhill side of adjacent rows.
Other structures which have utilized guide paths to attempt to guide processing implements, but which have not utilized the structure of the present invention include:
U.s. pat. No. 1,241,173 to Von Meyenburg in September of 1917; PA0 U.s. pat. No. 1,608,666 granted to Plum in November of 1926; PA0 U.s. pat. No. 1,723,073 granted to Poll in August of 1929; PA0 U.s. pat. No. 2,948,543 granted to Collier in August of 1960; and PA0 U.s. pat. No. 3,127,689 granted to Hopkins in April of 1964; PA0 U.s. pat. No. 7961 granted to Pierce in September of 1866; PA0 U.s. pat. No. 264,434 granted to Benson in September of 1882; PA0 U.s. pat. No. 291,975 granted to Benson in January of 1884; PA0 U.s. pat. No. 502,712 granted to Freeman in August of 1893; and PA0 U.s. pat. No. 1,113,492 granted to Schlicht in Oct. of 1914.
The present inventor initially experimented with structures such as shown in the patent to Collier, but found that the "boat hull" effect of the guide means caused too much friction, excessive wear, and not precise guidance. The structure was abandoned in favor of the structure of the invention as set out in claims herein.
Other patents which were cited in a search of the prior art, and which are believed to be at least somewhat pertinent include:
Applicant is aware of no other prior art which would affect the patentability of his invention.